The invention relates to an actuation microsystem made on a flat substrate and comprising at least:                a pivoting arm mounted in rotation around a hinge formed on the substrate,        a first stationary contact pad arranged on a top surface of the substrate and operating in conjunction with at least one movable contact pad securedly affixed to the pivoting arm,        and an end of opening travel stop of the pivoting arm.        
The invention also relates to a method of fabrication of one such microsystem.